100-107 monoisotopic M+H= 842.5099 VATVSLPR
90-99 monoisotopic M+H= 1045.5642 LSSPATLNSR
50-69 monoisotopic M+H= 2211.1046 LGEHNIDVLEGNEQFINAAK
See for example Matsui et al Electrophoresis 18:409 Figure 2D. I am
confident there are many other references to these peaks in the literature.
We regularly use the 842 peak and the 2211 peak as internal standards. The
1045 peak is usually weaker.
Ken Parker
PerSeptive Biosystems